It's not a dream. I think it's more like it's simply the fact that humans exist, but demons don't. Devil people, the Devil, succubi, incubi, whatever, don't exist. Well, supposedly. I don't think you can actually prove whether or not they do or don't exist, so they're classified as nonexistent for simplicity.

The human characters aren't any more real than the demonic characters are, it's just that since they are something that is confirmed as existing, they're able to maintain their existence there.

(Also "flashes of anger" isn't a thing that's exclusive to devil people, even if Fuchsia were human she'd still have "flashes of anger" because either way she'd have emotions and anger is an emotion. And this strip doesn't even remotely depict any such "flash of anger" if anything she's merely irritated or frustrated with the fact she can't enter the reality zone.)_________________

So heres the thing: if you assume that because the devil-people (I guess Succubi?) didn't exist in the reality zone, and neither did the Devil, that this is just a dream, or perhaps an "escape for reality sort of deal". But how does that work with multiple "real" characters inhabiting it? How would multiple people share the same fantasy world? GAH THE CONFUSION.

Repeat to yourself "It's just a strip, I should really just relax..."

ADDENDUM

"Succubi" is not a generic term for Devil People but is instead, well, see for yourself:

Such manly hands..._________________Opinions are like ass holes: everybody has them. Sometimes they're clean... sometimes they stink... and sometimes they're just full of shit. But if you love shoving yours up on other people's faces, then you're a fucking whore.

While the majority of the Reality Zone art is of excellent quality, I would like to say that there is one flaw that I have noticed. Her horns. In the Reality Zone panels, they appear to simply be sitting on top of her hair, like berets. This kinda throws me off a little, as most horns instead upthrust out of the skull of a creature. So her hair should be flowing around them, perhaps allowing for a little peek at scalp.

It's a minor quibble, I admit. But I'm just trying to give an honest opinion for the sake of Tat's art. These little Reality Zone strips are clearly attempts to stretch his artwork skills, and I'd like to see his skills improve.

As for how Fuschia's body reacts to the zone, it doesn't actually strike me as 'demons don't exist', but more along the lines of how much abuse demons reputedly put their bodies through (or the bodies of those they possess, if you prefer). Deterioration is bound to happen, and rapid aging is likely how it would look.

Succubus, dictionary definition: A demon assuming female form that visits men in their sleep or contemplation to tempt them into lust (Fuchsia and Blue's original function vis-a-vis Slickie, though he was anything but contemplative...)

Also, we do not know when or how Fuchsia assumed her current condition (just that she "wasn't always" one). Could have been within a regular human lifetime or could have been many centuries back. Strip evidence seems to indicate being bomfed into a succubus causes a mindwipe at least the first time it happens, so she may have been another random passerby bomfed on D's whim, or a onetime soul-sale customer for whom enslavement was the catch in the deal -- and she herself would not really know. So yes, in the RZ she may start aging and crumbling into dust.

We have seen that Li'l E can exist fine in the Reality Zone, and even Forky does not disappear but merely becomes inanimate. Big D may avoid the RZ not necessarily because it may erase him but because it would render him powerless (which to him is the same).

The way I read the RZ, everyone has in their life a bit of a subjective reality into which fit the narrative of their lives, their feelings, their self-image and worldview, that is both self-generated and by reference to how others see you or how you think they see you. Those others have their own subjective read on what your "self" is in relation to their world. Those visions may or may not stand up too well, or at all, to the light of objective reality.

Pebbles also exists fine in the Reality Zone. She only started burning because she was wearing Seymour's Holy Cap._________________Opinions are like ass holes: everybody has them. Sometimes they're clean... sometimes they stink... and sometimes they're just full of shit. But if you love shoving yours up on other people's faces, then you're a fucking whore.

Well, we already know that not everything in the Reality Zone functions according to reality as we know it.

When was the last time you saw anyone's hand start to crumble like it was made of plaster?

Yes but if it's due to age then imagine her true age must be something older than a mummy. Lots of mummys and very ancient artefacts crumble when exposed to the elements. So reality is just giving her body the reaction it would have if oxygen and other elements were an opposing force in the Sinfest World (which being that it's a cartoon world they are not)

2) Is it just me, or did Fyoosh' RZ-face posess the most mongoloid(asian) features of all ?

3) Squigly and Forky - as they crossed RZ borders, they were rendered unconscious or paralyzed, yet they did not disintegrate. Fyoosh pattern is opposite, she kept her agility and reasoning but started to dissipate. That brightly shown her emotional world, but is it consistent and what could it mean ?
She was just like Pygmalion's statue, detached from time flow, and suddenly meeting the History.

Well, we already know that not everything in the Reality Zone functions according to reality as we know it.

When was the last time you saw anyone's hand start to crumble like it was made of plaster?

Yes but if it's due to age then imagine her true age must be something older than a mummy. Lots of mummys and very ancient artefacts crumble when exposed to the elements. So reality is just giving her body the reaction it would have if oxygen and other elements were an opposing force in the Sinfest World (which being that it's a cartoon world they are not)

Oxygen. Required to live. One of the most destructive forces in the universe.

Not at all. For Fyoosh the RZ is no more real than Wonderland for us.
She just feels like Winny the Pooh now. She realized that inevitably as Criminy grows mature - he would lean more and more to reality.

She makes him grow - but that alienate him from her.

That is the conflict. She cannot conservate Crim, and she cannot let him go.
I think she looks at Crims evolution kinda the same as Blue looks at hers.

Given external factors like D, she can try to resist or runaway and hide, but when the factor is the very essence of Crimm there is not much she can do.

She never even bothered to think about RZ before, until she saw that Crim is pulled into it.